This disclosure relates to reinforcing materials that are useful in the manufacture of pipes, rods, conduits and conduit bundles for undersea deployment, and the wrapping of pipes, rods, conduits and conduit bundles with these materials.
Filament reinforced tapes have been used in the construction of undersea conduit or in the assembly of conduit bundles. For purposes of this disclosure, the term “conduit” may be understood to broadly refer to any tube for transporting one or more utilities such as natural gas, oil, water, electrical cable, optical filament, phone cable, and the like. The term “tubular member” is used herein to more broadly refer to tubular members such as pipes and rods, as well as conduits. In a more particular example, the conduit may be an unbonded, flexible, continuous, spoolable tube. One tape that has been used for this purpose is a glass filament reinforced tape available commercially from 3M Company under the designation Scotch 890 Filament tape. This tape is advertised as having an initial tensile strength of 600 lb/in width, but when tested in sea water at up to 70° C. its strength degrades rapidly and it is not desirable for long term, e.g., 25 year service life, undersea applications.
U.S. Pat. No. 6,641,330 illustrates one application of filament-reinforced tapes to undersea conduit wherein a plurality of undersea conduits are bound together using filament-reinforced tapes as the conduits are payed out and laid at sea. Scotch glass filament-reinforced tape 8981 is disclosed as being suitable for this purpose. In another application, filament-reinforced tapes have been used in the construction of undersea conduit to provide a filament-reinforced inner layer that is used to bind metal wire or band reinforcements that are wound around an intermediate polymeric tube that is fabricated during the manufacturing process. However, for each of these applications, it is desired that the filament-reinforced tape retain its properties for up to 25 years when the tape is deployed under seawater. In particular, this means that the tape should be resistant to high external pressures at depths up to 3,000 meters and resist the corrosive effects of seawater.
Accordingly, there is a need for a flexible filament-reinforced material or pressure sensitive adhesive tape for building and/or wrapping or binding undersea conduit.